1. Field of the Invention
The invention relates to a motorcycle tire with a tread in which tread grooves are cut transversely or obliquely relative to the circumferential direction and in which the grooves define corresponding profile blocks between them.
2. Description of the Related Art
Conventionally, rolling surfaces or tread surfaces of motorcycle tires were provided with encompassing grooves, the depth of which was approximately equal to their width. Such relatively wide and deep encompassing grooves, however, caused a relatively low leaning stiffness in the tires, so that sufficient driving stability in the high-speed range was no longer assured. Also, a low axial stiffness of the tread resulted, which impaired the transfer of transverse forces between the motorcycle and the road surface.
The conditions were then improved with a tire tread with a strongly transversely oriented tread design, as described in European non-prosecuted, published application EP-A-0 145 009. That tread, however, was still provided with a center groove. The tire of that publication was much superior with respect to the above-described, previously conventional groove treads as concerned their drive stability and force transfer characteristics.
A further step in improving the leaning drive stiffness and the transferability for braking forces and lateral forces was a tread which did not include any encompassing grooves or circumferentially oriented groove segments. That tire is described in brochures of the firm Metzeler Reifen GmbH under the name "ME 1 Front", for instance. In many respects, that tread provides virtually perfect drive characteristics.
There are motorcycles, however, which have a tendency to jitter or shimmy. Such handle jitter is usually due to the frame structure, the geometry and the load distribution. The effect is observed in a velocity range of between 40 and 80 km/h (25-50 mph). Handle jitter is a motorcycle-typical oscillation of the steering system about the steering axis at a frequency of about 7 Hz.